Following the passage of the fifteenth amendment (March 30, 1870) granting all male citizens the right to vote, Southern states took immediate steps to prevent blacks from exercising their voting rights. These included establishing poll taxes, literacy tests, property and registration requirements, and the "grandfather clause," which allowed an individual to vote only if his grandfather could vote as of January 1, 1866. (The poll tax would finally be outlawed by the twenty-fourth amendment, adopted in 1964.) In 1875, Tennessee's "Jim Crow" laws legalized the segregation of public facilities. In 1896, the U.S. Supreme Court, in Plessy vs. Ferguson, decreed "separate but equal" accommodations for African Americans. And in 1918, the end of World War I launched a renewed wave of violence against blacks when, as U.S. soldiers, they had experienced a respite from racism overseas and returned to their homes and demanded their civil and human rights. Hundreds were lynched, some still in uniform. The violence culminated in the Red Summer of 1919, when race riots erupted in July in the District of Columbia, and twenty-five major American cities.
The post-World War II years saw a continuation of the black struggle for equal rights, which held little hope. According to a report from the Southern Regional Council, in 1947, only 12 percent (around 600,000) of African Americans living in the South were eligible to register to vote. In 1948, President Truman signed Executive Order 9981, ending segregation in the U.S. armed forces, but integration was not officially "completed" until six years later (October 1954).
